Broken URLs in old presentations

[ellessenne]

Hi,

While I was working on #157 I noticed that there are several other broken URLs (e.g., in older presentations).

Should we aim to fix those or leave it be until we actually experience some issues?

[danielinteractive]

Thanks @ellessenne , yeah unfortunately we don't have a GHA with a URL check yet, maybe we should add that to prevent this. But if you have some corrections, sure, that would be great!